It seems to be a rite of passage that "young adults" in the US (classified as those between the ages of 18 and 34, per the US Census Bureau) take a bit of guff from the generations that preceded them. Millennials, ID'd by Pew Research as those born between 1981 and 1997, haven't escaped this fate, but while many label the current younger set as simply hanging out "in the basement playing video games," as USA Today notes, that's not quite the case. The Census Bureau released a population report Wednesday that looks back at the 18-34 demographic over the past four decades, comparing today's young adults to those going back to 1975. "If one theme describes how adulthood has changed over the last 40 years, it is growing complexity," the report notes. A few notable trends stand out, and the internet is buzzing about them: